Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare read-only and closed-world, and the description adds meaningful context: the index includes score, trend, and pinned methodology_version, is weekly, and has a 31-year history. This goes beyond the annotation by clarifying what the returned data contains and its update cadence.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact yet informative, with the main return value front-loaded, followed by usage triggers and update frequency. Every sentence contributes value without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple read-only tool with one optional parameter fully described in the schema, the description covers the essential aspects: what is returned (score, trend, methodology_version), when to use it, and how often it updates. No output schema exists, but the enum of returned components is stated.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema fully documents the single optional 'days' parameter (100% coverage), so the baseline is 3. The description adds no additional parameter semantics beyond what the schema already states about returning a history series instead of the current snapshot.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Returns') and clearly identifies the resource: a 0-100 federal regulatory-activity index based on Federal Register volume and trend, with 31-year weekly history. It is highly specific and distinguishable from the many sibling tools, even without naming an alternative.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides an explicit 'Call when' list covering relevant user intents (rulemaking pace, regulation volume, Federal Register activity) and use cases (monitoring, compliance briefs, alert gating). However, it does not include when-not scenarios or name alternative tools, so it does not fully meet the 5-level criterion.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.